Gas-mask eye piece mounting



Patented May/16, 1939 UNITED STATES GAS-MASK EYE PIECE MOUNTING Joseph B. Dym, Pittsburgh, Pa., assignor to Mine Safety Appliances Company, Pittsburgh, Pa., a' l corporation of Pennsylvania Application December 5, 1936, Serial No. 114,407

, 5 Claims.

This invention relates to gas mask eye-piece mountings.

Present-day gas masks make use of a facepiece which makes a gas-tight fit with the face and head. To be eiective, therefore, it is necessary that accessories, such as eye-pieces, shall likewise be perfectly gas-tight. In the construction of gas masks there have commonly been used flat eye-pieces, and various constructions are available for suitably sealing such eye-pieces against leakage. However, the eye-piece is one of the most important elements of the gas mask 4because its utility is impaired unless adequate vision is maintained. To increase the eld of vision it would be desirable to use larger eyepieces than can satisfactorily be provided in flat, or plane, form, 'such as those of the so-called aviation type, which are large eye-pieces of lenticular form and curvilinear from side to side. Difiiculties have been countered in adequately andeconomically sealing such aviation-type eyepieces in the facepiece. For instancenot only is it more diiiicult to secure the eye-piece by the procedures used with flat eye-pieces, but also those procedures result normally in rather high breakage and thisL is most objectionable in the case of aviation-'type eye-pieces whichin the most approved form are ground to provide distortionless vision, and may cost several dollars per pair. y

It is among lthe objects of this invention to provide a gas mask having aviation-type eyepieces which are adequately sealed against leakage, which are'simple, sturdy, easily constructed,l

inexpensive, and do not add materially to the weight of the mask or render it cumbersome, which provide/maximum angle of vision, which are retained firmly in place, and in the mounting of which breakage is eliminated or reduced to. a negligible extent. The invention may be described with reference to the accompanying drawing in which Fig. 1 is a vertical plan view of the iront of a gas mask face-piece provided with eye-pieces in `accordance with the preferred embodiment of the invention; Figs. 2 and 3 sectional views through the eye-piece taken' on lines II--II and III-III, respectively; Fig. 4 an enlarged fragmentary view of a portion of Fig. 2; and Fig. 5 a view like Fig. 4 showing a modiii'cation. I In accordance lwith the linvention the eyepiece is mounted within a groove annularly positioned in the eye-piece aperture, and the eyepiece is firmly held therein and sealed against leakage by an endless Vz netallic grommet which is fitted without mechanical or die compression exteriorly of the 'opening in such manner as to continuously compress the material fromV which the face-piece is constructed against .the eyepiece to form and maintain a gas-tight seal between it and the face-piece.

Having reference now lto the drawing, Fig. 1

shows a face-piece I of conventional form made from any suitable exible material, such as rubber, in accordance with standard practice. The face-piece and its accessories, apart from the eye-pieces, may assume variousiforms, and they play no part in this invention. However, the form shown is provided withan opening 2 for receiving an intake tting leading from a canister containing purifying material, or from a regenerating device, and with anextension 3 for receiving a ilutter Valve or` the like exhalatlon device. x

The face-piece is provided with apertures I for receiving .aviation-type eye-pieces 5, which, as shown, are of generally lenticular outline and continuously curvilinear from side to side, as appears particularly from Figs. 1 and 3. In -accordance with the invention the apertures are defined by forwardly projecting flange members 6 which are molded integrally with the facepiece. Each iiange is provided interiorly with an annular groove' f'I in which the eye-piece is mounted. The flanges 6 are suitably so constructed that apertures 4 conform initially rather closely to the contour of the eye-pieces 5, and groove l in each aperture is preferably of such size as to receive the eye-piece with little or no expansion Qf the Iiange so that the rubber of the iiange is not placed under tension when the eye-piece is inserted.

With this construction the face-piece is not distorted when the eye-pieces are inserted. Since, however, the insertion of the eye-piece does not place the rubber of the flange under tension, means must be used not only to seal the l eye-piece against leakage of gas, but also vto positively and satisfactorily retain the eye-piecev in position. To this end a grommet member 8 is applied, after the eye-piece has been positioned within groove l, to compress the ange material around and against the eye-piece and tov retain it rmly in position and form a satisfactory gas-tight seal to prevent ingress of untreated air into the face-piece..v l Grommet 8 is in the form of a continuous ring corresponding generally to the contour of the eye-piece, as shown in Fig. 1.l It is of U-shaped section, having an outer leg 9 which overlies the outer portion of flange 6 and presses it against that part of the eye-piece disposed within the groove, as seen in Figs. 2 to 4. The grommet at the outer end of leg 9 is bent rearwardly and then downwardly around a bead I0 which projects peripherally from the outer end of the flange 6, thus forming an inner leg 9a which t presses against flange 6 peripherally of eyepiece 5. The grommet thus compresses the rubber ilange material rearwardly against the forward surface of the eye-piece about its edge, and also compresses the flange material peripherally of the eye-piece entirely about its edge.

In this embodiment the inner leg 9a of the grommet is so positioned that its outer surface lies in or inwardly from the general vertical plane of the inner surface of eye-piece 5. Fig. 4 shows a construction in which the "outer surface of .leg 9a of the grommet is substantially aligned with the inner surface of eye-piece 5, but as just indicated leg 9a may press ilange 6 at a point farther inward, as shown in Fig. 5. The advantage of this is that the rubber of ange 6 is compressed by the end of leg 9a in such manner as to resist or prevent the grommet from snapping oil the harige, thus insuring a firm and safe mounting of the eye-piece.

Most suitably flange 6 is also provided with a bead Il; Fig. 4, extending outwardly from and framing the eye-piece opening. The lower end of leg 8 of the grommet seats against this bead, as seen in Figs. 1 and `4. This bead acts to prevent tearing out of the rubber from around the eye-piece when the face-piece is pulled in the vicinity of the eye-pieces, as in placing the mask on the face.

'Ihe grommets are preshaped to the form shown in the drawing, and to final size, so that when applied they will effect the desired compression and sealing. The eye-piece having been inserted in groove 1, one end ofthe grommet is applied toone end of flange 5 and bead I0 is forced into the Vopening formed between the inner and outer legs of the grommet. 'I'he bead is then progressively tucked in toward the other end of the grommet, thus effecting the mounting shown in the drawing. In this manner the rubber of iiange 6 is forced toward the edge-of eyepiece 5 by the end of the inner leg- 9a of the grommet. Likewise, leg 9 forces the outer wall of the groove inwardly against the eye-piece so that its surface adjacent its edge is peripherally pressed by the rubber of the flange.

The grommet, being continuous and being applied without being compressed, crimped, or

otherwise acted upon mechanically, is made of such size as to achieve the foregoing action. 'I'he compression of the rubber by the grommet is desirable not only because it insures satisfactory sealing and rm retention of the eye-piece, but

. no mechanical treatment during or after application, in contrast to the prior practice of using split rings and the like requiring die compression.

Such fitting of the grommet to the flange, as contrasted with the prior practice of compression of the grommet itself, as by dies, is of material advantage. That is, in die compressing grommets about lenses in gas mask face-pieces there is a substantial amount of breakage. That loss is not critical in the case of plane lenses, but it becomes of major consequence in the use of aviation-type lenses because the best specifications require these to be ground to avoid distorted vision, wherefore they are quite expensive. 'Ihe simple tting of the grommets in the practice of the present invention avoids such breakage of the eye-piece lenses.

While the invention has been described with particular reference to gas masks provided with two eye-pieces, it will be understood that it is equally applicable to face-pieces provided with a single eye-piece of width sufiicient to give the desired angle of view. Also, while the invention is adapted particularly to the mounting of curvilinear lenses, it will be understood also that it is applicable to the mounting of plane lenses.

According to the provisions of the patent 'statutes, I have explained the principle and mode of construction of my invention and have illustrated and described what I consider to be its best eml bodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. In a gas mask, goggle or the like, the combination of a flexible member adapted to engage in sealed relation with the face of the wearer, said member having an opening therethrough for an eye or the like of the wearer, an integrally molded upstandng ilange bounding the eye opening on the side of the flexible member away'from the face of the wearer, an integrally molded 'substantially annular body/ having substantially a U-shape in cross section secured at one side of the base of its U-shaped body to the upstandng flange and extending so that the legs of the U- shaped body are directed substantially radially inwardly of the opening, a. transparent closure member received in the substantially annular groove provided between the legs of the U-shaped body, an endless one-piece grommet of stiff material, and of substantially a J-shape in cross section surrounding the U-shaped body and constructed and arranged s o that the leg of the J- shaped grommet lies over the leg of the U-shaped body remote from the flexible member to force the leg into sealing relation with the closure member and the hook of the J-shaped grommet lies over and forces the base of the U-shaped body radially thereof into sealing relation with the periphery of the closure member, said inner periphery of the edge of the hook of the J-shaped grommet being of greater length than the outer periphery of the closure member, and an integrally molded ilange on that leg of the U-shaped body which engages the leg of the J-shaped grommet, said ange extending over the.r leg of the J-shaped grommet and serving to hold the grommet and leg of the U-shaped body in proper assembly.

2. vIn a gas mask, goggle or the like, the combination of a ilexible member adapted to engage with the face of the wearer, said member having an opening therethrough for an eye or the like of the wearer, an upstandng flange bounding the eye opening on the side of the flexible member away from the face of the wearer, a substantially annular body having substantially a. U-shape in cross section secured to the upstanding flange and ,extending so that the legs of the U-shaped body are directed substantially radially inwardly of the opening, a closure member received in the substantially annular groove provided between the legs of the U-shaped body, a grommet of stiff material, and of substantially a J-shape in cross section surrounding the U- shaped body and constructed and arranged so that the leg of the J-shaped grommet lies over the leg of the U-shaped body remote from the exible member to force the leg into sealing relation with the closurefmember andthe hook of the J-shaped grommet lies over and forces the base of the U-shaped body radially thereof into sealing relation with the` periphery of the closure member, said inner periphery of the edge ofthe hook of the Il-shaped grommet being of greater length than the outer` periphery of the closure member, and a flange on that leg of the U-shaped body which engages the leg ofl vthe J-shaped grommet, said iiange extendingover the leg of the J-shaped grommet and serving to hold the grommet and leg of the U-shaped body in proper assembly.

3. In a gas mask, goggle or the like, the combination of a flexible member adapted to engage in sealed relation with the face of the wearer, said member having an opening therethrough for an'eye or the like of the wearer, an integrally molded substantially annular body having substantially a U-shape in cross section secured to the edge of the opening in the flexible member and extending so that the legs of the U-shaped body are directed substantially radially inwardly of the opening, va closure member received in the substantially annular groove provided between the legs of .the U-shaped body, and 'an endless 40 one-piece grommet of stid material, and of substantially a J-shape in cross section surround-V ing the U-shaped body and constructed and arranged so that the leg of the J-shaped grommet lies over the leg of the U-shaped body remote from the flexible member to force the leg into sealing relation with the closure member and the hook of the J-shaped grommet lies over and forces the base of the U-shaped body radially thereof into sealing relation with the periphery of the closure member, said inner periphery of the edge of the hook of the J-shaped grommet being'of greater lengthrthan the outer periphery of the closure member. l,

4. In a gas mask, goggle or the like, a facepiece of ilexible material having an opening therethrough, a forwardly projecting flange of compressible material surrounding the opening and having an annular groove formed interiorly thereof, a closure member set in the groove, and an endless grommet engaging with the flange to compress it radially against the outer periphery of the closure member, one edge of the grommet extending radially within the radially outer pe riphery of the closure member and the other edge of the grommet terminating radially outwardly of the radially outer periphery of the closure member s that the grommet can be removed by further compressing that portion of the flange positioned radially outside of the annular groove.

5. In a gas maslzg, goggle or the like, a facepiece of flexible material having an eye opening therethrough, a forwardly projecting flange surrounding the opening and having an annular groove formed interiorly thereof, an eye-,piece set in the groove, a grommet engaging with the flange to compress it against the eye-piece, and a lip on the ange directed substantially radially outwardly of the opening and engaging with and extending over the grommet.

'- JOSEPH B. DYM. 

